Yeah, I'd say it's innate it some people. It can also be taught to some degree with correct technique and body mechanics, but there are people who just have it - I guess it's in the way their body moves and functions as a kinetic chain. Lucky folks they are.

i'm glad you asked that because i know all about this. if you punch a heavy bag in the same spot, your mate can stand to the side and tell you how much it moved. if he says it moved a lot, then you hit real hard. if it doen't move a great deal then not so much. get your mate to see how much you move the bag compared top fighters and bob's your uncle, i would imagine.

Jimmy that is correct however the other method is also to kidnap a tramp - assuming you dont have a heavy bag, not everyone does... then hit said tramp, then get pro fighter to hit same said tramp and ask tramp to compare the shots.

I find this method works best also if your mate is not trustworthy and may lie to you about bag movement.

Some guys just pack a big punch, but there still needs to be some technique as well. In my experience power in kicks is much more down to tecnique especially mid and high kicks. I've got pretty weak skinny legs but I've always thrown hard kicks off of both legs, possibly partly to do with playing a lot of football when I was young but mainly down to good tecnique and flexibility